Medical instrument

Abstract

The present disclosure provides a medical instrument, including a tubular main body; a plurality of operating lines; an operating part main body provided on the base end portion of the tubular main body; a bending operating part which is configured to bend a distal portion of the tubular main body; a path defining part which is configured to define a path of the operating line in the bending operating part; and a deviation preventive member which is configured to prevent the operating line from deviating from a path defined by the path defining part; wherein the operating line becomes in a relaxed state when the bending operating part is in a fixation position, while the operating line becomes in a strained state when the bending operating part is in an operation position.

The invention claimed is: 
     
       1. A medical instrument, comprising:
 a flexible tubular main body; 
 a plurality of operating lines inserted into the flexible tubular main body such that each of the operating lines has a tip end portion connected to a distal portion of the flexible tubular main body; and 
 an operating part comprising an operating part main body positioned in a base end portion of the flexible tubular main body and a bending operating part configured to rotate relative to the operating part main body and to slide between a fixation position and an operation position such that the bending operating part bends the distal portion of the flexible tubular main body by individually applying a pulling force to the plurality of operating lines via rotation of the bending operating part, 
 wherein the operating part includes a path defining part that defines a path of each of the operating lines inside the operating part, and a deviation preventive member that prevents each of the operating lines from deviating from the path defined by the path defining part and has a notched portion through which the operating lines pass, the deviation preventive member is formed such that a peripheral boundary edge of the notched portion has a chamfered shape in which the peripheral boundary edge is rounded in a thickness direction of the deviation preventive member, a base end portion of each of the operating lines is fixed to the bending operating part, when the bending operating part is at the fixation position, the operating lines are in a relaxed state, and when the bending operating part is at the operation position, the operating lines are in a state that is more strained than the relaxed state. 
 
     
     
       2. The medical instrument according to  claim 1 , further comprising:
 a slider configured to slide relative to the operating part main body between a projection position and a retraction position such that slider restricts the rotation of the bending operating part when the slider is at the projection position and allows the rotation of the bending operating part when the slider is at the retraction position, 
 wherein the deviation preventive member has a notched portion for the slider through which the slider is configured to pass, and when the slider slides between the projection position and the retraction position, the slider passes through the notched portion for the slider. 
 
     
     
       3. The medical instrument according to  claim 2 , wherein the deviation preventive member is configured to be fitted into the path defining part. 
     
     
       4. The medical instrument according to  claim 3 , wherein the path defining part comprises a plurality of rib shaped portions positioned to surround the plurality of operating lines in the paths. 
     
     
       5. The medical instrument according to  claim 4 , wherein the plurality of rib shaped portions of the path defining part comprises a first pair of rib shaped portions and a second pair of rib shaped portions positioned such that the deviation preventive member is configured to be fitted into a space formed between the first and second pairs of rib shaped portions. 
     
     
       6. The medical instrument according to  claim 2 , wherein the path defining part comprises a plurality of rib shaped portions positioned to surround the plurality of operating lines in the paths. 
     
     
       7. The medical instrument according to  claim 6 , wherein the plurality of rib shaped portions of the path defining part comprises a first pair of rib shaped portions and a second pair of rib shaped portions positioned such that the deviation preventive member is configured to be fitted into a space formed between the first and second pairs of rib shaped portions. 
     
     
       8. The medical instrument according to  claim 1 , wherein the deviation preventive member is configured to be fitted into the path defining part. 
     
     
       9. The medical instrument according to  claim 8 , wherein the path defining part comprises a plurality of rib shaped portions positioned to surround the plurality of operating lines in the paths. 
     
     
       10. The medical instrument according to  claim 9 , wherein the plurality of rib shaped portions of the path defining part comprises a first pair of rib shaped portions and a second pair of rib shaped portions positioned such that the deviation preventive member is configured to be fitted into a space formed between the first and second pairs of rib shaped portions. 
     
     
       11. The medical instrument according to  claim 1 , wherein the path defining part comprises a plurality of rib shaped portions positioned to surround the plurality of operating lines in the paths. 
     
     
       12. The medical instrument according to  claim 11 , wherein the plurality of rib shaped portions of the path defining part comprises a first pair of rib shaped portions and a second pair of rib shaped portions positioned such that the deviation preventive member is configured to be fitted into a space formed between the first and second pairs of rib shaped portions. 
     
     
       13. The medical instrument according to  claim 1 , further comprising:
 a slider configured to slide relative to the operating part main body between a projection position and a retraction position such that slider restricts the rotation of the bending operating part when the slider is at the projection position and allows the rotation of the bending operating part when the slider is at the retraction position. 
 
     
     
       14. The medical instrument according to  claim 13 , wherein the deviation preventive member is configured to be fitted into the path defining part. 
     
     
       15. The medical instrument according to  claim 13 , wherein the path defining part comprises a plurality of rib shaped portions positioned to surround the plurality of operating lines in the paths. 
     
     
       16. The medical instrument according to  claim 15 , wherein the plurality of rib shaped portions of the path defining part comprises a first pair of rib shaped portions and a second pair of rib shaped portions positioned such that the deviation preventive member is configured to be fitted into a space formed between the first and second pairs of rib shaped portions. 
     
     
       17. The medical instrument according to  claim 1 , wherein the bending operating part comprises a dial configured to rotate relative to the operating part main body and to slide between a fixation position and an operation position such that the bending operating part bends the distal portion of the flexible tubular main body by individually applying the pulling force to the plurality of operating lines via rotation of the bending operating part. 
     
     
       18. The medical instrument according to  claim 17 , further comprising:
 a slider configured to slide relative to the operating part main body between a projection position and a retraction position such that slider restricts the rotation of the dial when the slider is at the projection position and allows the rotation of the dial when the slider is at the retraction position. 
 
     
     
       19. The medical instrument according to  claim 18 , wherein the path defining part comprises a plurality of rib shaped portions positioned to surround the plurality of operating lines in the paths. 
     
     
       20. The medical instrument according to  claim 19 , wherein the plurality of rib shaped portions of the path defining part comprises a first pair of rib shaped portions and a second pair of rib shaped portions positioned such that the deviation preventive member is configured to be fitted into a space formed between the first and second pairs of rib shaped portions.